'\" t
.\"     Title: debugfs_use_file_start
.\"    Author: [FIXME: author] [see http://docbook.sf.net/el/author]
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: January 2017
.\"    Manual: The debugfs filesystem
.\"    Source: Kernel Hackers Manual 4.8.15
.\"  Language: English
.\"
.TH "DEBUGFS_USE_FILE_STA" "9" "January 2017" "Kernel Hackers Manual 4\&.8\&." "The debugfs filesystem"
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.SH "NAME"
debugfs_use_file_start \- mark the beginning of file data access
.SH "SYNOPSIS"
.HP \w'int\ debugfs_use_file_start('u
.BI "int debugfs_use_file_start(const\ struct\ dentry\ *\ " "dentry" ", int\ *\ " "srcu_idx" ");"
.SH "ARGUMENTS"
.PP
\fIdentry\fR
.RS 4
the dentry object whose data is being accessed\&.
.RE
.PP
\fIsrcu_idx\fR
.RS 4
a pointer to some memory to store a SRCU index in\&.
.RE
.SH "DESCRIPTION"
.PP
Up to a matching call to
\fBdebugfs_use_file_finish\fR, any successive call into the file removing functions
\fBdebugfs_remove\fR
and
\fBdebugfs_remove_recursive\fR
will block\&. Since associated private file data may only get freed after a successful return of any of the removal functions, you may safely access it after a successful call to
\fBdebugfs_use_file_start\fR
without worrying about lifetime issues\&.
.PP
If \-\fBEIO\fR
is returned, the file has already been removed and thus, it is not safe to access any of its data\&. If, on the other hand, it is allowed to access the file data, zero is returned\&.
.PP
Regardless of the return code, any call to
\fBdebugfs_use_file_start\fR
must be followed by a matching call to
\fBdebugfs_use_file_finish\fR\&.
.SH "COPYRIGHT"
.br